Let the gelatin bloom by combining the gelatin powder and cold water. Set aside.

Beat the egg and sugar until pail and thick. Then put the bowl on top of a pot with simmering water.

Slowly pour in the milk while stirring. Stir the mixture until thick and can coat a back of a spoon.

Combine the flavouring and bloomed gelatin. Stir until completely mixed.

Remove bowl off the simmering water. Let cool for a bit, be careful not to let the gelatin set.

In a separate bowl, whip up the heavy cream.

Fold the whipped cream into the cool custard mixture. (The custard mixture has to be cool enough so that the cream won't melt in it.)

The bavarois is now then ready to be molded/used as desired.

*40g of flavouring is just a rough measurement guide for the flavour you wish to make. What I normally do is add the flavouring without even measuring, then taste the custard. The taste I'm looking for has to be a bit strong, so once the whipped cream is incorporated, the taste would be just right.